External-internal cranial expansion to treat patients with craniocerebral disproportion due to post-shunt craniosynostosis: a case series.

INTRODUCTION: Secondary craniosynostosis subsequent to shunting is one of the late complications of ventricular shunt placement in the early childhood. Several interventions have been used to treat high intracranial pressure associated with this condition. This study aimed to evaluate the patients' clinical symptoms and head circumference before and after a method of decompressive craniotomy, coined as external-internal cranial expansion (EICE). METHODS: A retrospective study was conducted, and the patients who had undergone EICE for the treatment of post-shunt craniosynostosis between 2010 and 2020 were enrolled. This approach was a combination of a hinge multiple-strut decompressive craniectomy and internal cranial flap thinning by drill. Data, extracted from medical records, were used to evaluate the patients' symptoms and head circumferences before and 12 months after surgery. RESULTS: A total of 16 patients were enrolled in the study, of which eight were females. Before the surgery, 9 patients (56.2%) suffered from visual impairment, and all had intractable headache. Papilledema was recorded in all, with 3 cases having optic disc paleness. After cranial expansion, only two patients had headaches, diagnosed as migraine-type and psychosomatic headaches, respectively. In two patients, progressive visual impairments got worsening after surgery, which would be due to severe preoperative optic nerve atrophy. Patients' head circumferences significantly increased after the surgery (mean of 48.97 ± 4.28 cm vs. 45.78 ± 4.31 cm; P value < 0.0001). CONCLUSION: In lower resource countries, where newer technologies like distraction osteogenesis is not easily available, external-internal cranial expansion can be considered an effective alternative for patients with post-shunt craniosynostosis.

Alternative phenotypes of male mating behaviour in the two-spotted spider mite.

Severe intraspecific competition for mates selects for aggressive individuals but may also lead to the evolution of alternative phenotypes that do not act aggressively, yet manage to acquire matings. The two-spotted spider mite, Tetranychus urticae, shows male mate-guarding behaviour and male-male combat for available females. This may provide opportunity for weaker males to avoid fighting by adopting alternative mating behaviour such as sneaker or satellite tactics as observed in other animals. We investigated male precopulatory behaviour in the two-spotted spider mite by means of video-techniques and found three types of male mating behaviour: territorial, sneaker and opportunistic. Territorial and sneaker males associate with female teleiochrysales and spend much time guarding them. Territorial males are easily disturbed by rival males and engage themselves in fights with them. However, sneaker males are not at all disturbed by rival males, never engage in fights and, strikingly, never face attack by territorial males. Opportunistic males wander around in search of females that are in the teleiochrysalis stage but very close to or at emergence. To quickly classify any given mate-guarding male as territorial or sneaker we developed a method based on the instantaneous response of males to disturbance by a live male mounted on top of a brush. We tested this method against the response of the same males to natural disturbance by two or three other males. Because this method proved to be successful, we used it to collect territorial and sneaker males, and subjected them to morphological analysis to assess whether the various behavioural phenotypes are associated with different morphological characters. However, we found no statistical differences between territorial and sneaker males, concerning the length of the first legs, the stylets, the pedipalps or the body.

Suitability of the predatory mites Iphiseiodes zuluagai and Euseius concordis in controlling Polyphagotarsonemus latus and Tetranychus bastosi on Jatropha curcas plants in Brazil.

One of the most promising plant species for biofuel production in Brazil is the physic nut Jatropha curcas. Major phytosanitary problems include the attack of two pest mite species, the broad mite Polyphagotarsonemus latus and the spider mite Tetranychus bastosi. Owing to pesticide-related problems, there is an increasing demand for sustainable environmental-friendly control methods such as biological control. In this study we evaluated the suitability of the predatory mite species Iphiseiodes zuluagai and Euseius concordis in controlling P. latus and T. bastosi on J. curcas. The number of T. bastosi killed by I. zuluagai was lower than the number of P. latus consumed. Euseius concordis preyed upon both T. bastosi and P. latus but the number of prey killed was always lower in comparison with I. zuluagai. However, P. latus and T. bastosi are suitable for the development of I. zuluagai and E. concordis as oviposition of both predators did not differ in relation to prey species. The preference of I. zuluagai for leaves of plants infested by either P. latus or T. bastosi, combined with the higher values for predation obtained by this predatory mite when fed on P. latus, compared to those values obtained by E. concordis, suggests that I. zuluagai can be more efficient than E. concordis in reducing populations of P. latus and T. bastosi under field conditions. Furthermore, we report here on the first record of predatory mites associated with P. latus and T. bastosi on native J. curcas plants in Brazil. In conclusion, we emphasize the crucial importance of predatory mites as agents of natural biological control of mite pests on J. curcas in small farms.

Candidate predators for biological control of the poultry red mite Dermanyssus gallinae.

The poultry red mite, Dermanyssus gallinae, is currently a significant pest in the poultry industry in Europe. Biological control by the introduction of predatory mites is one of the various options for controlling poultry red mites. Here, we present the first results of an attempt to identify potential predators by surveying the mite fauna of European starling (Sturnus vulgaris) nests, by assessing their ability to feed on poultry red mites and by testing for their inability to extract blood from bird hosts, i.e., newly hatched, young starlings and chickens. Two genuine predators of poultry red mites are identified: Hypoaspis aculeifer and Androlaelaps casalis. A review of the literature shows that some authors suspected the latter species to parasitize on the blood of birds and mammals, but they did not provide experimental evidence for these feeding habits and/or overlooked published evidence showing the reverse. We advocate careful analysis of the trophic structure of arthropods inhabiting bird nests as a basis for identifying candidate predators for control of poultry red mites.

A new method for mite extraction from leaf samples.

Debris often hampers the detection of mites in washed leaf samples. We describe in detail a method for the extraction of mites from leaf samples, based on the adherence of mite cuticles to liquid paraffin, at the interface of paraffin and ethanol in a so-called mite-counting channel. We demonstrate its efficacy by comparing the mite numbers in samples before and after extraction. We illustrate the method's reliability by extracting known numbers of a taxonomic variety of plant-inhabiting mites, manually added to mite-free debris: for 13 of the 15 taxa all mites were retrieved. This method can also be used to extract small non-mite arthropods such as scales, whiteflies, thrips, cicadellids, hymenopteran parasitoids and psyllids.

The benefits of clustering eggs: the role of egg predation and larval cannibalism in a predatory mite.

Many arthropods produce clusters of eggs, but an unambiguous explanation for the evolution of egg clustering is still lacking. We test several hypotheses for the production of egg clusters by the predatory mite Iphiseius degenerans. This predator feeds on pollen, thrips larvae and nectar in flowers, but oviposits in clusters in tufts of leaf hairs (acarodomatia), where eggs run a lower risk of being killed by thrips, the prey of this predatory mite. The observed clustering is not caused by a shortage of oviposition sites; females preferably oviposit in a domatium containing eggs rather than in an empty domatium. To explain this preference, we first examined the effect of egg clusters on the risk of cannibalism. We found that eggs are invulnerable to cannibalism, whereas larvae emerging from single eggs or from clusters were equally vulnerable. Subsequently, we considered the killing of eggs resulting from counter-attacks by prey, i.e. the western flower thrips. We found no indication that a cluster of eggs protects eggs from predation by thrips. However, when eggs were clustered in a domatium rather than scattered over domatia, the proportion of eggs killed by thrips was lower. Hence, oviposition in clusters has no effect on its own and oviposition in domatia reduces predation risk by thrips, but oviposition in clusters in domatia leads to a synergistic effect on the survival of predator eggs. This synergism probably arises because eggs in clusters within tufts of leaf hairs are more difficult for thrips to reach. These experiments highlight a novel explanation of egg clustering, i.e. adaptation to counter-attacking prey. Moreover, they show that plant domatia protect predator eggs from predation.