Discontinuous diet alters fitness and flight behavior of Hippodamia convergens (Coleoptera: Coccinellidae)

Hippodamia convergens is a native insect predator providing widespread biocontrol of aphids and other insect pests in the High Plains.  Agricultural crops are subject to harvesting cycles and other disturbances such as drought and pesticide usage, creating landscapes with discontinuous resource availability for insect predators.  These temporal discontinuities in agricultural landscapes can interfering with feeding and overall performance for these biocontrol agents. The metabolic budget of insect predators necessarily alters the ‘spending’ on both reproduction and dispersal, influencing their predatory performance in the field. We examined the impact of pulsed (i.e., discontinuous) feeding schedules versus continuous resource provisioning on the reproduction and dispersal capacity of adult H. convergens beetles, using tethered flight as a proxy for dispersal before and after 18 reproductive days.  Adults were provided two levels of access to prey over 48h periods: 12h (high access) or 6h (low access) either continuously or discontinuously. Fewer insects broke reproductive diapause on discontinuous diet and oviposition was delayed in both high and low food treatments. Low food treatments lowered both fecundity and fertility. Reproductive history was also found to reduce future flight potential. Negative effects of diet discontinuity at this small scale can indicate how resource availability gaps alter lady beetle population dynamics and ecosystem services in the wider agricultural landscape. Understanding how resource timing alters lady beetle performance can improve conservation strategies for land management and conservation biological control.