Search Results

You are looking at 1 - 10 of 10 items for :

  • Author or Editor: G. Evans x
  • Biology and Life Sciences x
Clear All Modify Search

The family Encyrtidae is one of the largest families among the Chalcidoidea with over 3000 nominal species known throughout the world of which thirty-eight have been recorded in Egypt (Abd-Rabou, 2006). It represents the largest group of natural enemies of soft scales (Coccidae: Hemiptera) with several hundred species in 45 genera. Prinsloo (1997) provided an excellent review and key to the genera of encyrtids associated with soft scale insects. The following represents the results of a survey of encyrtid parasitoids associated with scale insects in Egypt (Hemiptera: Cocciodea) conducted in 2009.

Restricted access

Species of the family Aphelinidae (Hymenoptera: Chalcidoidea) comprise many of the most widely used and successful entomophagous biological control agents. An annotated list of the 11 genera and 81 species of the family Aphelinidae known to occur in Egypt and a key to genera of Aphelinidae in Egypt are provided.

Restricted access

An annotated list of 68 species in 35 genera of encyrtids known to occur in Egypt with their insect or plant hosts and distribution is provided.

Restricted access

During an investigation of the whitefly fauna in Egypt, Pealius mori (Takahashi) was discovered infesting Euphorbia sp. in Giza, Egypt. This is the first record of the presence of this whitefly species in Egypt and on this host plant. The taxonomy, distribution, host plants, parasitoids as well as comments regarding this whitefly species are presented.

Restricted access

Recently, the senior author discovered the presence of a whitefly on sugarcane, Saccharum officinalis , in Qena, Egypt, and sent specimens to the junior author who identified it as Bemisia formosana Takahashi (Homoptera: Alyerodidae). Since this is the first report of this species occurring on sugarcane, an economic crop, and the first distribution record of it occurring in Egypt and the Mediterranean region, we thought it expedient to publicize the information to alert workers in the region to its presence.

Restricted access

In recent years, Aleuroclava psidii (Singh) (Hemiptera: Aleyrodidae) has been extending its geographic range due to the international movement of plant material. In October 2013, it was discovered on Psidium sp. (Myrtaceae) in Egypt and represents the first record of this species in Egypt and the Western Palearctic region.

Restricted access

Species of the family Signiphoridae (Chalcidoidea) are primarily hyperparasitoids associated with scale insects, whiteflies and mealybugs through other Chalcidoidea; however, certain species are primary parasitoids of these hosts. Recent collections and a review of the literature indicate that the following five species of the family Signiphoridae are known to occur in Egypt: Chartocerus niger (Ashmead), Chartocerus subaeneus (Főrster), Signiphora fax Girault, Thysanus sp. and Signiphora flavella Girault, the latter newly recorded in Egypt and Palearctic region. A key to the Egyptian signiphorid species is included.

Restricted access

Blepyrus insularis (Cameron) (Encyrtidae) was reared from Phenacoccus parvus Morrison, an invasive mealybug recently found infesting Psidium sp. in Egypt. Encarsia cibcensis Lopez-Avila (Aphelinidae) was reared from Aleuroclava psidii (Singh) (Hemiptera: Aleyrodidae), an invasive whitefly found on Ficus sp. in Egypt. Mesopeltita truncatipennis (Waterston) (Pteromalidae) was reared from the lecanodiaspid scale, Lecanodiaspis africana (Newstead) (Hemiptera: Lecanodiaspididae) on Ficus sp. All of these represent new host records for the parasitoids.

Restricted access

The mango shield scale, Milviscutulus mangiferae (Green) (Hemiptera: Coccidae), a serious pest of mango trees in various parts of the world, is reported on Mangifera indica in Egypt which represents the first record of this species in the country.

Restricted access
Acta Biologica Hungarica
Authors: Elizabeth C. Cropper, C. G. Evans, J. Jing, A. Klein, A. Proekt, A. Romero and S. C. Rosen

Although feeding in Aplysia is mediated by a central pattern generator (CPG), the activity of this CPG is modified by afferent input. To determine how afferent activity produces the widespread changes in motor programs that are necessary if behavior is to be modified, we have studied two classes of feeding sensory neurons. We have shown that afferent-induced changes in activity are widespread because sensory neurons make a number of synaptic connections. For example, sensory neurons make monosynaptic excitatory connections with feeding motor neurons. Sensori-motor transmission is, however, regulated so that changes in the periphery do not disrupt ongoing activity. This results from the fact that sensory neurons are also electrically coupled to feeding interneurons. During motor programs sensory neurons are, therefore, rhythmically depolarized via central input. These changes in membrane potential profoundly affect sensori-motor transmission. For example, changes in membrane potential alter spike propagation in sensory neurons so that spikes are only actively transmitted to particular output regions when it is behaviorally appropriate. To summarize, afferent activity alters motor output because sensory neurons make direct contact with motor neurons. Sensori-motor transmission is, however, centrally regulated so that changes in the periphery alter motor programs in a phase-dependent manner.

Restricted access