The way Martin Robe, district commissioner of Melsetter, tells it, his is the area of the country hardest hit by the guerrilla war.

Convoys heading for Fort Victoria and onward to South Africa along the main road running through his district in eastern Rhodesia are regularly ambushed by guerrillas. Forty-two whites have been killed by them in the past three years, and of the 160 white farmers once settled around Melsetter town fewer than 10 now remain.

As for Cashel, a town in his district bordering on Mozambique that once had 110 white farmers, "You can count them on the fingers of one hand," Robe said.

In Nyanyadzi itself, guerrillas have burned out a row of shops along the highway and killed or kipnaped their owners. Taking reporters and observers to a polling station farther down the road would have been "too dangerous" because of the likelihood of land mines, Robe remarked.

Melsetter district, he said, harbors somewhere between 300 and 450 "terrorists," as the authorities refer to the nationalist guerrillas, and is no place for visitors to go wandering about without a large military escort.

Melsetter seems a good microcosm of the tug-of-war under way all across Rhodesia for control both of the land and allegiance of the 6.8 million blacks. It also provides some insight into the government strategy to take the war to the guerrillas following the elections and some evidence that many nationalists may be wavering in their loyalty to their leaders, who are determined to fight on.

From most appearances and even official accounts, Melsetter, like a number of other eastern and western border district, already had fallen largely under guerrilla control. In fact, a fair portion of Rhodesia's countryside has become a patchwork of areas dominated by guerrillas and government troops, with each side periodically attacking into the other's territory.

Some guerrilla "patches," the african tribal trust lands, are virtually on the outskirts of the capital. In addition, the guerrillas seem to be solidly entrenched in a 50-to-100 mile-wide strip running along most of the country's border. Short of manpower, the government has lately concentrated on defending the white farms and urban areas in the country's center.

Traveling through these guerrilla-dominated areas is postively eerie, as reporters taken right to the Mozambican broder during the April elections found out. The scattered local population just ignored the heavily armed convoy while the soldiers guarding it kept grenade launchers, heavy machine guns and NATO FN rifles at the ready for an ambush at any moment.

Flying over the country is just as unnerving. Light, slow-moving aircraft hopscotch from one white area to another, carefully trying to avoid the trust lands known to be heavily infiltrated by guerrillas, some having antiaircraft batteries and surface-to-air missiles.

Yet it still remains mostly a shadowy war of long range shellings, quick ambushes and nighttime hit-and-run attacks on farms and lighting forays into the cities. "Contact," as an exchange of fire is called, are common, but rarely do the two sides stand and fight in sustained close combat.

This may change soon. The guerrillas travel in much larger groups more regularly now - 50 to more than 100 - and are becoming more aggressive.

A district commissioner near Melsetter let slip in his briefing to foreign correspondents that a dozen guerrillas had ambused a convoy of 30 to 40 government soldiers in his area recently. Around Salisbury, guerrilla commandos sometimes steal cars and Land Rovers and drive in for their attacks on homes, farms and police stations in the white suburbs.

Robe, however, says that the election of the new government under a black president and prime minister should lead to a radical change. "I think it's correct to say a lot of terrorists are going to come and hand themselves in after the elections," he remarked. "A lot of them are just sitting on the fence, waiting to see."

This widespread belief among whites and blacks involved in setting up the new black-led government is based partly on the failure of the estimated 12,000 guerrillas inside the country to launch a promised general offensive to halt the April elections.

In fact, the war seems to have pretty much picked up where it left off briefly during the elections, when the guerrillas would have been foolhardy to challenge the 70,000 to 100,000 Rhodesian security forces mobilized for the occasion.

Rhodesia's war strategists have seized upon a risky new tactic in a bid to resolve their acute military manpower shortage and to try to retake lost territory from the guerrillas.They are raising what some call a "people's army" of auxiliaries.

These auxiliaries already number between 7,500 and 10,000, or nearly a third of the rougly 30,000 members of the regular security forces mobilized at any one time.

The tropps, renowned for their indiscipline and party partisanship are given only three to 10 weeks' training instead of six months, paid a nominal monthly salary of $30 to $38 and dressed in a motley array of uniforms.

The government is pumping them by the hundreds into the most delicate and severely war-affected areas of the country, including the tribal trust lands around the capital and those alonge the eastern border like the one here and in nearby Maranke.

Guerrilla spokesman in Zambia and Mozambique do not seem to take the auxiliaries as much of a threat.

"Do you really think some one with three weeks' training is going to become a problem for us?" asked a spokesman for Patriotic Front leader Robert Mugabe in Lusaka. "They will be swept away."

Mugabe and the other leader of the Front, Joshua Nkomo, have announced war plans for 1979 that include zeroing in on economic targets, road and rail links and white farm "to grind settler business to a halt."

Both leaders have pledged as well to step up their activity in Rhodesia's urban area.

Unlike the government, neither the Nkomo nor Mugabe wing of the Fron twas a manpower proble at this point. Both groups are swamped with refugees who provide a steady stream of recruits from their camps in Zambia, Botswana and Mozambique. There are probably close to 200,000 refugess living outside Rhodesia.

Each group has its special problems, however. Mugabe has been chronically short of arms and some of his guerrillas are sent into Rhodesia with old weapons and a pitifully small supply of ammunition, according to the Rhodesians. They concede, however, that he has successfully gotten the bulk of his forces once based in Mozambique into the country.

By contrast, Nkomo's guerrilla army has become almost trapped in its camps in Zambia and Angola where they have taken thousands of casualties from Rhodesian bombings and raids in the past six months. The Rhodesians estimate that there are only 2,000 to 2,500 nkomo guerrilla presently inside the country compare to Mugabe's 10,000 or more.

On the other hand, Nkomo boasts of plenty of arms and promises to introduce shortly "much more sophisticated weapons" into the war. He already has used SA7 portable missiles-provided by the Soviet Union or East Germany - from inside Rhodesia to shoot down two Air Rhodesia passenger planes. CAPTION: Picture 1, Armed Rhodesian women are a common sight. Darquennes/Sygma; Picture 2, Black civilians traveling on foot in the Rhodesian countryside are subject to checks by security forces. Sygma photos; Picture 3, Most Rhodesian whites learn to handle guns: Prime Minister Smith takes aim.