Suitability of leguminous cover crop pollens as food source for the green lacewing Chrysoperla externa (Hagen) (Neuroptera: Chrysopidae)

Abstract

Adequação do Pólen de Leguminosas Utilizadas em Adubação Verde como Fonte de Alimento paraChrysoperla externa (Hagen) (Neuroptera: Chrysopidae) RESUMO ABSTRACT -Diversification of crops with species that provide suitable pollen for predators may reduce pest population on crops by enhancing predator effectiveness. In this paper we evaluated the suitability of leguminous cover crop pollens to the predatory green lacewing Chrysoperla externa (Hagen). The predator is commonly found in coffee agroecosystems and the plant species tested were pigeon pea and sunn hemp, which are used in organic coffee systems. Newly emerged females and males of C. externa were reared on diets containing pollen of pigeon pea, sunn hemp, or castor bean, used as a control. The reproductive success of C. externa was evaluated when females fed the pollen species and when honey was added to the diets, to verify the predator need for an extra carbohydrate source. Similar intrinsic growth rates were found for females fed on pigeon pea pollen and on sunn hemp pollen but these rates increased significantly when honey was added to the diets. Females fed with pigeon pea pollen plus honey and with sunn hemp pollen plus honey had higher intrinsic growth rates than those fed with castor bean pollen plus honey. Females fed on castor bean pollen only or on honey only, did not oviposit. Leguminous pollen species were equally suitable for C. externa especially when they were complemented with honey. The results suggest that to successfully enhance predator effectiveness, organic coffee plantation should be diversified with plant providing pollen in combination with plant providing nectar.

Soil organisms associated to the weed suppressant Crotalaria juncea (fabaceae) and its importance as a refuge for natural enemies

“…The architecture of the stems and dense cultures of C. juncea favored by increased humidity and lower temperature, providing areas of refuge and shelter for parasitoids and predators, besides beneficial mites and nematodes in soil (McSorley et al, 2009). A greater number of Chrysoperla externa (Neuroptera: Chrysopidae) and higher levels of bee pollination were observed during the flowering period of C. juncea, because its yellow flowers had large amounts of pollen and gave off an attractive smell (Venzon et al, 2006). Natural enemies associated with C. juncea migrated to agricultural crops when the plants were grown in systems of rotation or succession (Gill et al, 2010).…”

Non-target effects of chlorantraniliprole and thiamethoxam on Chrysoperla carnea when employed as sunflower seed treatments

“…The larvae of Chrysoperla carnea (Stephens) feed on a wide range of small, softbodied arthropods with a preference for aphids (Principi and Canard 1984). Non-prey foods such as honeydew, floral and extrafloral nectar, and pollen can be important resources for chrysopids in both larval (Downes 1974) and adult (Venzon et al 2006) stages. Limburg and Rosenheim (2001) showed that extrafloral nectar was an important food source for neonate lacewing larvae on cotton and that its consumption increased as the availability of aphid prey declined.…”

Pollen resources used by Chrysoperla agilis (Neuroptera: Chrysopidae) in the Azores, Portugal

“…Agricultural ecosystems with a diversified flora and, consequently, a diversified pollen grain pool, may better promote the control of pests through greater predator efficiency (Venzon et al, 2006). Fitness of adult Chrysopidae depends on imaginal nourishment and pollen provides them with the nutrients necessary for oviposition (fertility) (Sundby, 1967).…”