Importance of host feeding for parasitoids that attack honeydew‐producing hosts

Abstract

Insect parasitoids lay their eggs in arthropods. Some parasitoid species not only use their arthropod host for oviposition but also for feeding. Host feeding provides nutrients to the adult female parasitoid. However, in many species, host feeding destroys an opportunity to oviposit. For parasitoids that attack Homoptera, honeydew is a nutrient-rich alternative that can be directly imbibed from the host anus without injuring the host. A recent study showed that feeding on host-derived honeydew can be an advantageous alternative in terms of egg quantity and longevity. Here we explore the conditions under which destructive host feeding can provide an advantage over feeding on honeydew. For 5 days, Encarsia formosa Gahan (Hymenoptera: Aphelinidae) parasitoids were allowed daily up to 3 h to oviposit until host feeding was attempted. Host feedings were either prevented or allowed and parasitoids had ad libitum access to honeydew between foraging bouts. Even in the presence of honeydew, parasitoids allowed to host feed laid more eggs per hour of foraging per host-feeding attempt than parasitoids that were prevented from host feeding. The higher egg-laying rate was not compromised by survival or by change in egg volume over time. In conclusion, host feeding can provide an advantage over feeding on honeydew. This applies most likely under conditions of high host density or low extrinsic mortality of adult parasitoids, when alternative food sources cannot supply enough nutrients to prevent egg limitation. We discuss how to integrate ecological and physiological studies on host-feeding behavior.

Fecundidad y alimentación de Tamarixia triozae (Hymenoptera: Eulophidae) sobre el psílido de la papa Bactericera cockerelli

“…These results reaffirm agencies that females actively search for prey hemolymph nutrients for egg production as noted by Jervis et al (2001), increased prey consumption can mean greater fertility, but also as the most longev females (59 days for this study) produced more eggs (529) compared with younger (10 d) which produced fewer eggs (31); This phenomenon has been observed in other micro-himenopetros as Encarsia formosa case Gahan (Burger et al, 2005).…”

“…These data differ significantly from those reported by Chien et al (1991) for the species T. radiata (Waterston) who said that this parasitoid is able to remove on average more than 500 nymphs, 80% by parasitism and predation remaining 20%, this difference may be due to T. radiata obtained possibly direct benefit to have sugary s excretions or host (honeydew) No so that it contains sugars, but also substantial amounts of amino acids that may use to parasitoids egg production as indicated by Burger et al ( 2005) in his study of E. formosa.…”

“…This reduced the pre-oviposition period, allows a biological control program by increasing the parasitoid can be released immediately after emergence, and can even be released in et al (2001), un mayor consumo de presas puede significar mayor fecundidad, aunque también las hembras más longevas (para este estudio 59 días) produjeron más huevos (529), comparado con las más jóvenes (10 d) que produjeron menor cantidad de huevos (31); este fenómeno ha sido observado en otros microhimenópetros como es el caso de Encarsia formosa Gahan (Burger et al, 2005).…”

“…Éstos datos difieren significativamente de los reportados por Chien et al (1991) para la especie T. radiata (Waterston) quienes señalan que éste parasitoide es capaz de eliminar en promedio más de 500 ninfas, 80% por parasitismo y el restante 20% por depredación, ésta diferencia puede deberse a que T. radiata posiblemente obtenga beneficios directos al disponer de las excreciones azucaradas de su huésped (mielecilla) que no sólo contiene azúcares, sino también cantidades importantes de aminoácidos que los parasitoides pudieran utiliza para la producción de huevos, como lo indica Burger et al (2005) en su estudio sobre E. formosa.…”

Effects of sugars on the longevity of adult females of Eretmocerus eremicus and Encarsia formosa (Hymenoptera: Aphelinidae), parasitoids of Bemisia tabaci and Trialeurodes vaporariorum (Hemiptera: Alyerodidae), as related to their honeydew feeding and host feeding

“…Jervis et al (1996) and Jervis and Heimpel (2005) stated that En. formosa females also obtain honeydew directly from the host's anus, and Burger et al (2004Burger et al ( , 2005 made the same statement; however, no such feeding behavior by En. formosa females was described by van Lenteren et al (1980) or observed by R. Arakawa (personal communication).…”