Female competition for availability of males in insects:the Nezara viridula(Linnaeus,1758)model

Multimodal communication in solitary stinkbugs enables them to meet,mate and copulate.Many plant-dwelling species exchange information during the calling phase of mating behavior using substrate-borne vibratory signals.A female-biased gender ratio induces rivalry and competition for a sexual partner.Female competition for males,first described among Heteroptera in three stinkbug species,revealed species specific differences and opened the question of plasticity in individually emitted temporal and frequency signal characteristics during calling and rival alternation.To address this question and gain an insight into the mechanisms underlying stinkbug female rivalry,we compared the characteristics of alternated signals in the southern green stinkbug Nezara viridula(Linnaeus,1758)(Hemiptera:Pentatomidae).Compared to male rivalry,female rivalry is more complex,lasts longer and runs through successive phases by a combination of different song types.The male pheromone triggers alternation between females,producing song pulses that occasionally overlap each other.One female initiates the rivalry by changing individual pulses into pulse trains of three different types.The competing female alternates with pulses of changed temporal characteristics at lower levels of rivalry and by varying the frequency characteristics of pulse trains at higher levels.During female rivalry,the male either stops responding or occasionally emits calling and courtship signals in response to the female that has produced signals of steady temporal characteristics.Female rivalry shows complex and species specific patterns of information exchange at different levels with a broad-range variation of temporal and frequency characteristics of,until now,unidentified vibratory emissions.

ABORT-like detector to combat active deceptive jamming in a network of LFM radars

This paper studies an electronic counter-counter measures（ECCM） scheme combating against deceptive electronic counter measure（ECM） techniques. An adaptive detector exploiting generalized likelihood ratio test（GRLT） criterion is applied to detect the presence of deceptive jamming in fractional Fourier transform（Fr FT） domain. First, the generating mechanism of spurious frequencies is analyzed based on the Volterra serial. The proposed nonlinear distortion model based on power amplifier behavior is robust in distortion analysis when the memory effect is considered.Second, a modified adaptive beamformer orthogonal rejection test（ABORT） like detector in closed form is built. The proposed detector can discriminate the echo and deceptive jamming adaptively by exploiting primary data and secondary data. This ECCM scheme is capable of guaranteeing the performance without the restriction of orthogonality, which is essential for the ABORT detectors. The expansion to radar network is discussed as a special case at the final part of this paper. Numerical simulations demonstrate the effectiveness of the proposed method.