Larvae of Cryptolaemus montrouzieri (Coleoptera: Coccinellidae) Prioritize Secretion of Protective Wax Over Daily Consumption and Growth.

In holometabolous insects, the immature or larval stage is characterized by a high rate of food consumption. The nutrients obtained from which are directed towards the maintenance of metabolism, growth, pupation, and metamorphosis. However, when resources are scarce, the lack thereof can affect the growth rate and compromise the metamorphosis and formation of adults. Do increased energy expenditures yield outcomes similar to those resulting from restricted food intake during the larval stage? We hypothesized that removing the wax layer from the larvae of the ladybird Cryptolaemus montrouzieri Mulsant, 1850 would result in increased energy expenditure, which can compromise both larval growth and adult size. We compared the development time, feeding rate, and adult size of larvae with an intact wax layer, and those with constantly removed wax layers. We found that the production of the wax layer was continuous. Unlike the waxed larvae, the larvae of C. montrouzieri extended their development time in response to energy depletion through wax removal. The total number of mealybugs consumed by waxless larvae was higher than the total number consumed by waxed larvae; however, the daily consumption of waxless larvae was lower than that of waxed larvae. Furthermore, the adults of waxless larvae were smaller than those whose larvae had intact wax layers. This suggests that the cost associated with wax layer secretion is a pivotal factor in larval growth. Removing this layer does not get compensated by increased larval feeding or extended development time.

The failed invasion of Harmonia axyridis in the Azores, Portugal: Climatic restriction or wrong population origin?

We tested two questions: (i) whether the climatic conditions of the Azorean Islands in Portugal may have restricted the invasion of Harmonia axyridis across this archipelago and (ii) determine what population of this species could have a higher probability of invading the islands. We used MaxEnt to project the climate requirements of different H. axyridis populations from three regions of the world, and the potential global niche of the species in the Azorean islands. Then we assessed the suitability of the islands for each of the three H. axyridis populations and global potential niche through histograms analysis, Principal Component Analysis (PCA) of climate variables, and a variable-by-variable assessment of the suitability response curves compared with the climatic conditions of the Azores. Climatic conditions of the Azores are less suitable for the U.S. and native Asian populations of H. axyridis, and more suitable for European populations and the global potential niche. The PCA showed that the climatic conditions of the islands differed from the climatic requirements of H. axyridis. This difference is mainly explained by precipitation of the wettest month, isothermality, and the minimum temperature of the coldest month. We concluded that the climatic conditions of the Azores could have influenced the establishment and spread of H. axyridis on these islands from Europe. Our results showed that abiotic resistance represented by the climate of the potentially colonizable zones could hinder the establishment of invasive insects, but it could vary depending of the origin of the colonizing population.

Invasion history of Harmonia axyridis (Pallas, 1773) (Coleoptera: Coccinellidae) in Ecuador.

Harmonia axyridis is a ladybird extensively used around the world for biological control of agricultural pests. However, it has become invasive in several countries, producing negative ecological and socio-economic impacts. Herein, we review the invasion history of the Harlequin Ladybird Harmonia axyridis (Pallas, 1773) in Ecuador. Although first reported in Ecuador in 2012, museum specimens date back to 2004 and it is currently established across the country, especially along the Andean region. Due to its invasive nature, further studies are urgently needed to evaluate possible impacts of H. axyridis on the Ecuadorian biodiversity and agroindustry.

First Occurrence of Cheilomenes sexmaculata (Coleoptera: Coccinellidae) on the Caribbean Island of Curaçao.

The predatory ladybird species, Cheilomenes sexmaculata (Fabricius), is native to Asia and Australia but has established populations outside its native range, most recently on the eastern and northern coast of South America. Here, we report for the first time the identification of the introduced ladybird beetle, C. sexmaculata, to the Caribbean islands, specifically the island of Curaçao. Although C. sexmaculata is typically considered beneficial and used as a means of biological control in continental ecosystems, due to its high predatory and reproductive ability, it has the potential to cause major ecological impacts as an invader to sensitive Caribbean island ecosystems.

Overview of the lady beetle tribe Diomini (Coleoptera: Coccinellidae) and description of a new phytophagous, silk-spinning genus from Costa Rica that induces food bodies on leaves of Piper (Piperaceae).

A new genus of lady beetle, Moiradiomus gen. nov. (Coleoptera: Coccinellidae Latreille, 1807: Diomini Gordon, 1999 ), and four new species are described from Costa Rica, representing the first known occurrences of obligate phytophagous lady beetle species outside of the tribe Epilachnini Mulsant, 1846 (sens. Slipinski 2007). The new species are described, illustrated and keyed, and their life histories discussed. Each species of Moiradiomus occurs on a separate species of Piper L., 1753 (Piperaceae Giseke, 1792), where the larva constructs a small silken tent between leaf veins and inside this shelter induces the production of food bodies, which are its exclusive source of food. Background information is provided on lady beetle trophic relations and other insect/Piper symbioses. The taxonomic history of Diomus Mulsant, 1850 and related species in the tribe Diomini is reviewed and existing errors in observation, interpretation, identification, and classification are corrected in order to provide a more meaningful context for understanding the new genus. The tribe Diomini is rediagnosed and recircumscribed to include Diomus, Decadiomus Chapin, 1933, Heterodiomus Brèthes, 1925, Dichaina Weise, 1923, Andrzej Slipinski, 2007, and Moiradiomus. Magnodiomus Gordon, 1999 and Erratodiomus Gordon, 1999 are removed from Diomini and transferred to Hyperaspidini Costa, 1849, subtribe Selvadiina Gordon, 1985 stat. nov. Mimoscymnus Gordon, 1994 and Planorbata Gordon, 1994, originally described in Coccidulini Mulsant, 1846 are also transfered to Hyperaspidini and placed in Mimoscymnina subtribe nov. (type genus Mimoscymnus). The main morphological characters distinguishing Diomini and Hyperaspidini are described and illustrated. A key to genera of Diomini sensu novo is provided. The identification of the Australian Diomus species illustrated in Gordon's publication on North American lady beetles is corrected from D. pumilio Weise, 1885 to D. tenebricosus (Boheman, 1859), however specimens recently collected in California do not match these genitalic illustrations and are identified as true D. pumilio. The following species of Diomus are transferred to Decadiomus as new combinations: D. balteatus (LeConte, 1878), D. floridanus (Mulsant, 1850), D. amabilis (LeConte, 1852), D. liebecki (Horn, 1895), D. myrmidon (Mulsant, 1850), D. humilis (Gordon, 1976), D. pseudotaedatus (Gordon, 1976), D. taedatus (Fall, 1901), D. bigemmeus (Horn, 1895), and D. austrinus (Gordon, 1976). Decadiomus seini Segarra, 2014 is placed as a junior synonym of D. austrinus. The following new species of Moiradiomus are described: M. clotho sp. nov., M. lachesis sp. nov., M. atopos sp. nov., M. nanita sp. nov.

The impact of six insecticides commonly used in control of agricultural pests on the generalist predator Hippodamia convergens (Coleoptera: Coccinellidae).

Hippodamia convergens is an important predator found in different agroecosystems. We evaluated the impacts of six insecticides on eggs, larvae and adults of this predator. For eggs, all insecticides reduced larval hatching rates, but did not affect egg duration. Chlorpyrifos and phosmet reduced larval survival; and chlorpyrifos, etofenprox and phosmet prolonged the larva development time. The survival and duration of pupae were not affected by all insecticides tested. Chlorpyrifos reduced fecundity, fertility and longevity when eggs were sprayed. For first-instar larvae, chlorpyrifos, etofenprox, phosmet and imidacloprid caused 100% mortality, while azadirachtin and thiamethoxam caused 35.0 and 52.7% mortality, respectively. However, azadirachtin and thiamethoxam did not affect the other biological parameters of the predator. In adults, chlorpyrifos, etofenprox and phosmet reduced adult survival. Chlorpyrifos, etofenprox, and phosmet reduced fecundity and longevity, but did not affect fertility. Azadirachtin, imidacloprid and thiamethoxam did not affect fecundity, fertility or longevity. Based on demographic parameters, all insecticides reduced the net reproductive rate (Ro), intrinsic rate of increase (r) and finite rate of increase (λ) of the predator when eggs were treated directly. Azadirachtin, chlorpyrifos, etofenprox and phosmet increased the mean generation time (T), while the effects of imidacloprid and thiamethoxam were similar to the control. When first-instar larvae were treated, azadirachtin and thiamethoxam reduced the Ro, r and λ. Thiamethoxam increased the T value, while the effects of the other insecticides were similar to the control. These insecticides should be used with caution, in order to reduce their harmful effects on the predator in agroecosystems.

Effect of different diets on biology, reproductive variables and life and fertility tables of Harmonia axyridis (Pallas) (Coleoptera, Coccinellidae)

ABSTRACT The biology, reproductive variables and population growth indicators of Harmonia axyridis (Pallas, 1773) (Coleoptera: Coccinellidae) fed on three diets, namely Cinara atlantica (Wilson, 1919) (Hemiptera: Aphididae), Brevicoryne brassicae (Linnaeus, 1758) (Hemiptera: Aphididae), and frozen eggs of Anagasta kuehniella (Zeller, 1879) (Lepidoptera: Pyralidae), were evaluated. With all three diets, birth rate was higher than mortality, resulting in positive rm values and thus indicating population growth. Under the conditions used in the experiments, H. axyridis was able to survive, develop and reproduce normally. This demonstrates that are different kind of food that can be essential for supporting the reproduction of some species of Coccinellidae, but not with the same optimization of preferred prey.

A new species of Scymnobius Casey (Coleoptera, Coccinellidae, Scymnini) from Pernambuco, Brazil

A new species of Scymnobius Casey (Coleoptera, Coccinellidae, Scymnini) from Pernambuco, Brazil. Scymnobius pernambucensis sp. nov. from Pernambuco, Brazil, is described and illustrated. This is the third species of this genus recorded from Brazil.

Effect of neem seed oil aqueous solutions on survival and development of the predator Cycloneda sanguinea (L. ) (Coleoptera: Coccinellidae) / Efeito de soluções aquosas de óleo de sementes de nim, Azadirachta indica, na sobrevivência e desenvolvimento do predador Cycloneda sanguinea (L. ) (Coleoptera: Coccinellidae)

The effects of the neem seed oil aqueous solutions on survival and performance of egg, larva and adult stage of the Coccinelid predator Cycloneda sanguinea (L.) were evaluated under laboratory conditions. In a first trial, eggs and 2nd-instar larvae were sprayed with the neem solutions at 0; 0.5 and 2.25 ml/l and kept at 25 ± 1°C, 70 percent RH and 14h photoperiod. Egg viability and duration and larvae and pupae survival were evaluated as well as the predatory capacity of the larvae, adult longevity and reproduction. Egg spraying did not affect egg hatch or larvae survival and development. When the larvae were sprayed, significant mortality was observed only at the higher concentration (P < 0.05) and larval development and predatory capacity were not affected. Also, adults originated from treated larvae showed no alterations on sex rate, fecundity, fertility and longevity, thus indicating that at the tested concentrations the neem oil do not reduce the reproductive potential of the species. In a second experiment, adults collected in the field were sprayed with neem oil or kept on Parthenium sp. twigs sprayed with the neem oil aqueous solution at 5 ml/l, to evaluate survival. The neem oil at this concentration caused no mortality to the adults, since all of them, sprayed or kept on sprayed twigs, presented a longevity curve similar to untreated ones. The results indicate that the neem oil presents potential to be used in association with biological control of pests, when C. sanguinea is present.

Os efeitos de soluções aquosas do óleo de sementes de nim sobre o predador Cycloneda sanguinea (L.), nos estágios de ovo, larva e adulto, foram avaliados em laboratório. Em um primeiro experimento, ovos e larvas de 2° ínstar foram pulverizados com as soluções de nim nas concentrações de 0; 0, 5 e 2,25 ml/l de água apresentaram mortalidade significativa (P < 0,05) somente na maior concentração e o desenvolvimento larval e a capacidade predatória não foram afetados. Os adultos originados de larvas tratadas não apresentaram alterações da razão sexual, fecundidade, fertilidade e longevidade, indicando que nas concentrações testadas o óleo de nim não reduz o potencial reprodutivo da espécie. Em um segundo experimento, adultos da joaninha coletados no campo foram pulverizados com a solução aquosa de óleo de nim ou mantidos sobre ramos de losna-branca pulverizados na concentração de 5 ml/l de água, para avaliação da sobrevivência. A pulverização do óleo de nim nesta concentração não causou mortalidade nos adultos de C. sanguinea, uma vez que os insetos de ambos tratamentos apresentaram curva de longevidade semelhante à da testemunha. Os resultados demonstram que o nim apresenta potencial para ser utilizado em associação com o controle biológico de pragas, quando C. sanguinea for empregada.