ALBERT

Description / Table of Contents: Summary Sideridis pallens, now common in the agrarian landscape, originated from habitats of the “Litoraea formations”. Under field conditions in NW Germany it has 2 generations per year. It belongs to the type with facultative larval diapause which is induced by short day and low temperature. According to the terminology ofH. J. Müller (1966) it could be best designated as diapauselike Oligopause. The summer generation develops in 6–8 weeks from the egg to the imago. The winter generation, from eggs laid in September, overwinters as larva 4 mainly in the stalks of plants and needs still 6–8 further weeks to continue the development to the adult during the spring. Young larvae differ from older ones in their behaviour, in their way of feeding and in the time of day activity. The developmental optimum lies at 28° C. At partly suboptimal conditions (short day and 20°, 15° and long day) the development is not completely arrested but retarded to 5–6 months. Even at optimal conditions a part of the population can undergo a spontaneous diapause with retarded development, this concerns likewise individuals hatched from the same egg cluster. The genetical variability of the diapause behaviour is regarded as an important ecological factor of adaptation to the environment. The offspring from individuals with delayed development showed the same retarded growth even when optimal conditions were given throughout their life. It is supposed therefore, that the stimuli releasing diapause already must have effected the parental generation. At normal development 6 larval stages occured, while at retarded deve- *** DIRECT SUPPORT *** AX104104 00003

Description / Table of Contents: Summary The antenna of the blowfly is composed of four parts: 1. scapus, 2. pedicellus, 3. funiculus and 4. arista. The joint between head-capsule and scapus does not participate in the movements of the antenna. All active movements are performed by the scapus-pedicellus-joint. The pedicellus can be turned upward and downward around a horizontal axis, inward and outward around a vertical one. These movements caused by four muscles of the pedicellus are probably perceived by bristles of the scapus. The morphological arrangement of the pedicellus-funiculus-joint permits only passive rotations of the funiculus around the longitudinal axis common to the funiculus and the pedicellus. These passive movements may be perceived by receptors in the pedicellus : the organ of Johnston and a large sensillum campaniforme. The funiculus-arista-joint, too, permits only passive movements: it bends when the arista is pushed towards the median plane, it is rigid when the arista is pushed backward. Therefore, forces acting on the arista from a frontal direction (for example by pressure from air current during flight) will cause the funiculus to turn outward around its longitudinal axis.

Description / Table of Contents: Summary 1. The brain of the ant Formica rufa has been studied (mushroom bodies; unstructured protocerebral neuropil, central body and deutocerebrum) with normal stains, silver impregnations, electron microscopy and lesions with subsequent degeneration of fibers. 2. The mushroom bodies mainly consist of four groups of nerve cells, differing in the location of the cell bodies and the structure of the dendritic arborizations. The axons of all these cells pass down the pedunculus; bifurcate and send branches to the \ga- and \gb-lobe. Little endings all over the axons are claimed to be synaptic regions. Lesions with following degeneration of the fibers show that axons of cell groups I and IV pass down to the \ga- and \gb-lobe in the middle of the neuropil. Groups II and III follow each other in the outer parts. \ldCentral endings\rd described by Trujillo-Cenoz and Melamed (1962) seem to belong to neurons from other lobes of the brain to the calyces, while the \ldthin fibers\rd are parts of mushroom body neurons. Terminations of neurons arising from other cells, connecting the mushroom bodies with sensory and motor lobes of the brain, are present all over the mushroom body neuropil. Endings in the calyx all show same structure. It could be pointed out that neurons of tracts originating from the antennal glomeruli and the lateral neuropil send arborizations in both calyces. Terminations of tracts ending in pedunculus, α- and β-lobe all are developped in the same manner, but differ from those in the calyx. Each ending is connected with many mushroom body neurons, covering a great part of the area of those lobes in cross sections. 3. Mushroom bodies, protocerebral bridge and central body are surrounded by a large mass of unstructured neuropil of the protocerebral lobes. In the anterior part of the protocerebrum the unstructured neuropil of both hemispheres is closely connected, but in the other parts a clear boundary between the two hemispheres exists and no connections \3- except few commissures \3- can be seen. Several different neuron systems have been found in the lateral lobes One system connecting the lobes with the calyces of the mushroom bodies and other tracts with arborizations in the pedunculus, one part entering the commissure dorsal of the central body, the other part terminating in the β-lobe of the other hemisphere. Further tracts are passing between ventral parts of the lateral neuropil and the central body. 4. The central body consists of three parts of neuropil, separated by cell-bodies. \ldHorizontal-systems\rd, fibers from the antennal glomeruli, lateral neuropil and \gb-lobes enter the sides of the central body neuropil, while \ldvertical systems\rd enter from ventral between the two \gb-lobes and dorsal, leaving the commissure between the two hemispheres. Two systems have been found connecting central body and mushroom bodies. Impregnations only show parts, so it is assumed that arborizations of these fibers also penetrate the unstructured protocerebral neuropil. 5. The antenno-motor center of the deutocerebrumis closely connected with protocerebral and subesophageal structures and shows equal distribution of neuropil unlike the sensory center, where synaptic glomerulus regions differ from the other parts of neuropil. The antennal nerve consists of about 60000 fibers, the major part entering the sensory center. Some fibers pass by and terminate in the antenno-motor neuropil. Three groups of fibers could be detected in the antennal nerve, but it only seems to be shure for one group (40000 fibers with 0,05-0,2 μ diameter per fiber) to function as sensory fibers. Each fiber only enters one glomerulus, so that each glomerulus is claimed to receive about 200 incoming antennal fibers. Outgoing tracts to other lobes of the brain are in connection with all parts of the sensory center and each fiber has its terminations in only one deutocerebral glomerulus. Segmental internuncials with cell-bodies lateral and medial of the neuropil unite several deutocerebral glomeruli. 6. Structure and function. It is tried to give some histological explanations for physiological results obtained by stimulation and lesions. Possible tracts for inhibition between the mushroom bodies and for connections between the mushroom bodies and the central body are enumerated. Structures and physiological results in the neuropil of the lateral protocerebral neuropil and their relations to the central body, pedunculi and calyces of the mushroom bodies are in accordance. The unstructured parts of the protocerebral neuropil seem to play an important coordinating role concerning integrative processes in the brain of insects.

Description / Table of Contents: Summary In the larva of Cerura vinula, on either side of the body a gland is found extending through the dorsal fat body of the mesothorax and the prothorax to the head. It is identified as the mandibular gland by its position and connection to the mandibula. Contrary to the mandibular glands of other species it does not contain an excretory duct. Probably it functions as an endocrine gland.