Many species adaptively alter offspring sex ratios, yet little is known about how they obtain relevant environmental information. New work on the parasitoid wasp Nasonia vitripennis reveals that the presence of eggs on hosts provides a reliable cue allowing females to determine the degree of local mate competition and adaptively adjust offspring sex ratios.

BACKGROUND A parasitoid wasp Hymenoepimecis manauara Pádua & Oliveira, 2015 was recorded parasitizing, for the first time, a female spider of Leucauge henryi Mello-Leitão, 1940 in the Amazon rainforest, Brazil. Images, description of the cocoon and comments about this interaction were added. NEW INFORMATION First record of Hymenoepimecis manauara parasitizing Leucauge henryi with description ...

Crocidosema aporema is a Neotropical Tortricidae moth that feeds on several wild and cultivated Fabaceae, has potential to cause economic damages. A new parasitoid wasp belonging the genus Meteorus (Hymenoptera, Braconidae), which been reared from C. feeding soybean in Brazil, described illustrated. checklist of parasitoids previously recorded for provided.

Our current, still limited, understanding of the comparative biology and evolution of polydnaviruses (PDVs) is reviewed, especially in the context of the possible origins of these parasitoid viruses and of their coevolution with carrier wasps. A hypothetical scenario of evolution of PDVs from ascovirus (or ascovirus-like) ancestors is presented, with examples of apparent extant transitional for...

BACKGROUND The parasitoid Jewel Wasp hunts cockroaches to serve as a live food supply for its offspring. The wasp stings the cockroach in the head and delivers a cocktail of neurotoxins directly inside the prey's cerebral ganglia. Although not paralyzed, the stung cockroach becomes a living yet docile 'zombie', incapable of self-initiating spontaneous or evoked walking. We show here that such n...

Plant viruses can profoundly alter the phenotypes of their host plants, with potentially far-reaching implications for ecology. Yet few studies have explored the indirect, host-mediated, effects of plant viruses on non-vector insects. We examined how infection of Cucurbita pepo plants by Cucumber mosaic virus (CMV) impacted the susceptibility of aphids (Myzus persicae) to attack by the parasito...

Parent-offspring conflict over clutch size may lead to siblicidal behavior between juveniles. In parasitoid wasps, selection for siblicide in small broods is predicted to produce a dearth of gregarious broods with few eggs. Here we document the clutch size distribution in the Bethylidae, a large family of aculeate parasitoids. Small gregarious clutches are the most common. Further data suggest ...

Parasitoid wasps lay female eggs or a high proportion of female eggs in favourable host insects because female wasps require many more resources during their development. Many studies have tested the effects of host physiological status on the sex allocation of parasitoids, but few have attempted to test the effects of host behavioural traits. Cotesia glomerata is a gregarious parasitoid wasp t...

Insect parasitoids and their insect hosts represent a wide range of parasitic trophic relations that can be used to understand the evolution of biotic diversity on earth. Testing theories of coevolution between hosts and parasites is based on factors directly involved in host susceptibility and parasitoid virulence. We used controlled encounters with potential hosts of the Aphidius ervi wasp to...

Recent studies have revealed that natural enemies can inßuence reproductive success of plants by eliminating their herbivores, thereby reducing damage to photosynthetic or reproductive tissues. Some plant species apparently have evolved “indirect defenses” in response to such top-down selective pressures, producing volatile compounds that are used as cues by natural enemies searching for their ...