Description of Bursaphelenchus abruptus n. sp. (Nemata: Aphelenchoididae), an Associate of a Digger Bee.

Bursaphelenchus abruptus n. sp., an associate of the digger bee, Anthophora abrupta (Hymenoptera: Anthophoridae), is described and illustrated. Bursaphelenchus abruptus n. sp. can be differentiated from other species of Bursaphelenchus by the absence of head annules, stylet length, length of the postuterine sac, shape of female tail, spicule morphology, and male caudal papillae arrangement. Two plant-pathogenic fungi, Monilinia fructicola and Botrytis cinerea, and a Monilia sp. isolated from an adult bee from Prince Georges County, Maryland, were good hosts for B. abruptus n. sp. Dauer juveniles (JIII) of B. abruptus n. sp. were isolated from the reproductive tracts of A. abrupta from Montgomery County, Alabama, for measurements and comparison with J2 -JIII inter-molts from a 4-week-old monoxenic culture on Monilia sp. Gonad lengths in dauer juveniles isolated from A. abrupta were highly variable (49 +/- 23 mum SD; range 21-93 mum; n = 29) compared with J2-JIII intermolts from culture (28 +/- 7 mum SD; range = 16-42 mum; n = 16), suggesting that postembryonic gonad development may continue while dauers are in the bee host. Adult males and females of B. abruptus n. sp. were examined with scanning electron microscopy (SEM) for ultrastructural comparisons with other members of the genus Bursaphelenchus.

Commensal nematodes in the glands, genitalia, and brood cells of bees (apoidea).

Seven species of bees from the eastern United States, representing four families in the Apoidea, were dissected and examined for nematode associates. Dufour's glands in females of Halictus ligatus, Augochlora pura mosieri, and Augochlorella gratiosa (Halictidae) from Florida were infested with dauer juveniles of Aduncospiculum halicti (Diplogasteridae). The Dufour's glands of Colletes thoracicus (Colletidae) females from Maryland were infested with dauer juveniles of a new species of Koerneria sp. (Diplogasteridae), and abdominal glands of females of Andrena alleghaniensis (Andrenidae) from New York were infested with dauer juveniles of another new species of Koerneria. The lateral and median oviducts, Dufour's glands, and poison sacs in females of Anthophora abrupta (Anthophoridae) from Maryland and Alabama were infested with dauer juveniles of a new species of Bursaphelenchus sp. (Aphelenchoididae). Cross sections of the nematode-infested poison sacs of A. abrupta revealed two types of humoral host defense reactions.

Floral Mimicry Induced by Mummy-Berry Fungus Exploits Host's Pollinators as Vectors.

Leaves and shoots of blueberries(Vaccinium spp.) and huckleberries (Gaylussacia sp.) when infected by ascospores of Monilinia spp. become ultraviolet-reflective and fragrant and secrete sugars at their lesions. Insects that normally pollinate these hosts are attracted to the discolored leaves, ingest the sugars, and transmit conidia to their flowers, resulting in sclerotia (mummy-berry) formation.

Occurrence and frequency of subgroup I-6 spiroplasma in arthropods associated with old fields in Maryland and Virginia.

The Subgroup I-6 spiroplasma, "Maryland Flower Spiroplasma," originally discovered on fall flowers and subsequently recovered from a syrphid fly and a beetle triungulin, was isolated from two new fall flower hosts and from the guts of nine nectar-imbibing insect species. These data, together with lack of recovery of I-6 spiroplasma from foliage-feeding, plant-sucking, or flightless flower-associated insects, suggest that I-6 spiroplasma may infect and be disseminated by nectar- or pollen-foraging insects, and that the dynamics of maintenance will prove to be complex.

Biological control in agroecosystems.

Living organisms are used as biological pest control agents in (i) classical biological control, primarily for permanent control of introduced perennial weed pests or introduced pests of perennial crops; (ii) augmentative biological control, for temporary control of native or introduced pests of annual crops grown in monoculture; and (iii) conservative or natural control, in which the agroecosystem is managed to maximize the effect of native or introduced biological control agents. The effectiveness of biological control can be improved if it is based on adequate ecological information and theory, and if it is integrated with other pest management practices.

Anthophora Bees: Unusual Glycerides from Maternal Dufour's Glands Serve as Larval Food and Cell Lining.

The Dufour's gland of Anthophora abrupta, a solitary bee, secretes a complex mixture of liquid triglycerides containing one long-chain and two shortchain fatty acids. This is applied inside the earthen brood cells and added to the provision, where it is converted, perhaps by enzymes from the bee's saliva or gut, to solid diglycerides that are later eaten by the bee larvae. This use of Dufour's gland secretion as food and its nutritive function are reminiscent of the royal jelly secreted by honey bees.

Natural Polyesters: Dufour's Gland Macrocyclic Lactones Form Brood Cell Laminesters in Colletes Bees.

Bees in the genus Colletes make their brood cells in the ground and coat them with a highly resistant, waterproof, transparent membrane. This membrane is a polyester constructed mainly from 18-hydroxyoctadecanoic acid and 20-hydroxy-eicosanoic acid, which are stored as their corresponding lactones in the Dufour's gland of the bee. When lining the cells, the bee secretes its glandular content, and the membrane is apparently a product of polycondensation reaction of its contents. This appears to be the first report of a naturally occurring linear polyester. The term laminester (lamina approximately layer + ester) for this class of compounds is proposed.

Alkali bees: response of adults to pathogenic fungi in brood cells.

Female alkali bees (Nomia melanderi) opened sealed cells containing brood infested with Aspergillus flavus, A. tamarii, Fusarium solani, Rhizopus sp., or Mucor sp. and filled them with compact soil, thus reducing fungus sporulation. Such awareness of the condition of sealed brood is hitherto unknown among solitary bees.